This study focuses on women who are planning to undergo surgery to remove one or both breasts, either to treat breast cancer or to prevent it (in women who are at very high risk for developing breast cancer). The purpose of the study is to test a drug, intended to prevent breast cancer, and to see if it has adequate absorption when applied as a gel to the skin. This would give women more options for breast cancer prevention in the future. Although there are medications that prevent breast cancer, their side effects discourage women from using them. Researchers believe that side effects can be reduced if drugs are absorbed through the skin (and don’t need to be taken as a pill by mouth). The study will compare the amount of a drug called telapristone that reaches different parts of the breast, when taken as a pill (the usual way) or when applied as a gel to the breast skin (the new way). The use of telapristone in this study is investigational.

Researchers test an experimental drug or treatment in a small group of people (20-80), to evaluate its safety and identify side effects. Often these trials are not disease specific and may include more than one type of cancer.

The experimental drug or treatment is administered to a larger group of people (100-300) to determine its effectiveness and to further evaluate its safety.

The experimental drug or treatment is administered to larger groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it with standard or equivalent treatment, and collect information that will allow the experimental drug or treatment to be used safely.